Screw.



0. REESE.

sc nnw. APPLICATION FILED FEB. 18, 1908.

Patented June 8,1909.

A TTOHNEYS OTTO REHSE, OF GERMANTOWN, CALIFORNIA.

\ SCREW.

Specification of Letters Patent.

Patented June 8, 1909.

Application filed February 18, 1908. Serial No. 416,449.

To all whom 'itmay concern:

Be it known that I, OTTO REHsE, a citizen of the United States, and aresident of Germantown, in the county of Glenn and State of California,have invented a new and Improved Screw, of which the following is afull,clear, and exact description. I

This invention relates to screws which have the threads discontinuous,so that cutting faces are provided transversely of the threads, whichserve to bore or drill an opening for the screw, and at the same time totap or thread the opening.

Anobject of the invention is to provide a simple and inexpensive screwfor wood-work and the like, which can be worked without difliculty, andwhich largely obviates the danger of splitting the wood.

The invention consists in the construction and combination of parts, tobe more fully described hereinafter and particularly set forth in theclaim.

Reference is to be had to the accompanying drawings formin a part ofthis specification, in which similar characters of reference indicatecorresponding parts in both views, and in which Figure 1 is a side viewof a screw showing my invention applied thereto; and Fig. 2 is anenlarged transverse section on the line 22 of Fig. 1.

Before proceeding to a more detailed explanation of my invention, itshould be understood that while the same is particularly useful inconnection with screws for carpentry, cabinet-making and other woodwork,it can also be advantageously applied to screws for other purposes. Whena screw is started, the taper of the same tends to.

force the wood apart and to split it. Furthermore there is oftenconsiderable difficulty in starting screws, particularly in hard woodand other materials which strongly resist the entrance of the screw. Iprovide a screw tapered to a point and having threads of any preferredor common form, but which, near the point, has longitudinal grooveswhich render the threads discontinuous and form cutting faces at thesame. These cutting faces act as do those of a male die or tap. Theybore or'drill an opening for the entrance of the screw, while at thesame time tically obviates the danger of splitting the material.

I preferably provide the screw with grooves of the form shown, forexample, in the accompanying drawings,- in which four grooves are usedand in which each forms, at the thread sections, cutting faces, whichare at substantially right angles and which lie in planes passingthrough the longitudinal axis of the screw.

Referring more particularly to the drawings, 10 represents the body ofthe screw which may be of'any preferred or common form. It has, forexample, the kerfed head 11, and the tapered portion 12 provided withthreads 13. Near the point 15, the screw has grooves 14arranged.longitudinally of the screw and extending to the point. Thegrooves are preferably V-shaped in cross section and each has one side16 arranged in a plane passing through the longitudinal axis of thescrew body. The sides 16 of the opposite grooves are alined and lie in asingle plane, which of course, passes through the longitudinal axis ofthe screw. The grooves lie at an angle with respect to the longitudinalaxis of the screw body, which 1s greater than the angle of taper of thescrew point. Consequently, the grooves which start at the point,gradually decrease in depth, and a short distance from the point, mergeinto the surface of the screw and cease. The

length of the grooves forms no part of my A screw comprising a bodyportion having a thread extending to its point and provided with aplurality of V-shaped grooves extending from the oint to about theunetion of the said point with the body, the

rooves bein oppositely arran ed and adl ially increasing in width froiiitheir l o wer to their upper .ends and merging at the upper and Widerends into the body, one of I In testimony whereof I have signed my thesides of the opposite grooves being in name to this specification in thepresence of alinement and in a plane passing through two subscribingwitnesses.

the longitudinal axis of the body and the other sides of said groovesbeing out ofl Witnesses:

alinement and in planes passing on opposite H. H. REESE, sides of thesaid axis.v T. J. HICKS.

OTTO REHSE.

